8mm Movie to Digital Service? - test-drb@ccmp.vtda.org

23 Apr 2013

ard at p850ug1.demon.co.uk (Tony Duell) wrote:
...
   Stupid
question but do those films (8" or 12") have sound on them  
 I am puzzled by your reference to 8" and 12" here.... Probably referring
to the reel size, which is of minor importance.

...
  like a track or are they purely video slides in a row?
(I've really 
 never seen them up close so hollywood is my only incorrect knowledge of 
 how it looks).  
...
  AFIAK 16mm cine film could have either an optical
soundtrack or a 
 magnetic one. In the former case, the ausio signal modulated a light 
 source which produced a variable width or density track on the film. 
http://en.wikipedia.org/wiki/Film_soundtrack
has an example of a 16mm film with variable width/area sound track.
I haven't been able to quickly find a reference picture for the variable
density (sometimes called "Western Electric") system, but it consists
of density gradients along the sound track (think "analogue bar code").

Magnetic sound track gives itself away as a strip of brownish color (like
audio cassette tape) that is laminated onto the film along one edge.
Sometimes there is a second "balance" strip along the other edge so the
film will spool up more evenly.

...
  After processing this was read using a lamp and
photocell, the signal
 from the latter was the original audio. Or a magnetic soundtrack, an 
 iron oxide 'stripe' down the film which works like a tape recorder. 
All three systems were available for 16mm film, my Siemens System 2000
projector would be capable of playing them all back. There is a switch 
at the amplifier (in the projector base) to select between optical and
magnetic audio and a knob on the optical reading head to select width
or density modulation.

...
  Super-8 8mm film could have a magnetic soundtrack (I
have never heard of 
 opticla sound on such films). I have also never heard of any soundtrack 
 on standard 8 ('double run 8(') or single-8 film.  
http://en.wikipedia.org/wiki/Super_8_film#Sound has the following:
"Super 8mm was also specified with an optical sound track. This occupied
the same location as the magnetic track. Picture to sound separation in 
this format was just 16 frames. Projectors and cameras obviously could 
not record sound in this system, but optical sound package movies became 
briefly popular, particularly in Europe (mainly because they were cheaper 
to produce - though the projectors cost more). Although the optical sound 
should have been inferior in quality to magnetic sound (running at 3.6 
inches per second for 24 frames per second), in practice it was often much 
better, largely because packaged movie magnetic sound was often poorly 
recorded."

No mention of audio tracks in any form in the Regular-8 article however.

Arno